| /* |
| * Copyright 2020 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package androidx.build.lint |
| |
| import com.android.tools.lint.client.api.UElementHandler |
| import com.android.tools.lint.detector.api.Category |
| import com.android.tools.lint.detector.api.Detector |
| import com.android.tools.lint.detector.api.Implementation |
| import com.android.tools.lint.detector.api.Issue |
| import com.android.tools.lint.detector.api.JavaContext |
| import com.android.tools.lint.detector.api.Scope |
| import com.android.tools.lint.detector.api.Severity |
| import com.intellij.psi.PsiModifier |
| import org.jetbrains.kotlin.asJava.classes.isPrivateOrParameterInPrivateMethod |
| import org.jetbrains.kotlin.idea.KotlinFileType |
| import org.jetbrains.uast.UAnonymousClass |
| import org.jetbrains.uast.UClass |
| |
| class PrivateConstructorForUtilityClass : Detector(), Detector.UastScanner { |
| |
| override fun getApplicableUastTypes() = listOf(UClass::class.java) |
| |
| override fun createUastHandler(context: JavaContext) = object : UElementHandler() { |
| override fun visitClass(node: UClass) { |
| if (node.isInterface || |
| node.hasModifierProperty(PsiModifier.ABSTRACT) || |
| node is UAnonymousClass || |
| // If this is a subclass, then don't flag it. |
| node.supers.any { !it.qualifiedName.equals("java.lang.Object") } || |
| // Don't run for Kotlin, for now at least |
| node.containingFile.fileType == KotlinFileType.INSTANCE |
| ) { |
| return |
| } |
| // If all constructors are already private or if not all methods are static then return |
| if ((node.constructors.all { it.isPrivateOrParameterInPrivateMethod() } && node |
| .constructors.isNotEmpty()) || |
| node.methods.any { !it.isStatic && !it.isConstructor } || |
| node.methods.none { !it.isConstructor } || |
| node.fields.any { !it.isStatic }) { |
| return |
| } |
| // This is a utility class with a non private constructor |
| context.report( |
| PrivateConstructorForUtilityClass.ISSUE, node, |
| context.getLocation(node.javaPsi), |
| "Utility class with non private constructor", |
| null |
| ) |
| } |
| } |
| |
| companion object { |
| val ISSUE = Issue.create("PrivateConstructorForUtilityClass", |
| "Utility classes should have a private constructor", |
| "Classes which are not intended to be instantiated should be made non-instantiable " + |
| "with a private constructor. This includes utility classes (classes with " + |
| "only static members), and the main class.", |
| Category.CORRECTNESS, 5, Severity.ERROR, |
| Implementation(PrivateConstructorForUtilityClass::class.java, Scope.JAVA_FILE_SCOPE)) |
| } |
| } |